#pragma once
#include<vector>

template<class T>
class Less
{
public:
	bool operator()(const T& x, const T& y)
	{
		return x < y;
	}
};

template<class T>
class Greater
{
public:
	bool operator()(const T& x, const T& y)
	{
		return x > y;
	}
};

namespace my
{
	template<class T, class Container = std::vector<T>, class Compare = Less<T>>
	class priority_queue
	{
	public:
		priority_queue() = default;

		template<class InputIterator>
		priority_queue(InputIterator first, InputIterator last)
			:_con(first, last)
		{
			for (int i = (_con.size() - 2) / 2; i >= 0; i--)
			{
				adjust_down(i);
			}
		}

		void push(const T& x)
		{
			_con.push_back(x);
			adjust_up(_con.size() - 1);
		}

		void pop()
		{
			std::swap(_con[0], _con[_con.size() - 1]);
			_con.pop_back();
			adjust_down(0);
		}

		const T& top()
		{
			return _con[0];
		}

		bool empty() const
		{
			return _con.empty();
		}

		size_t size() const
		{
			return _con.size();
		}

	private:
		void adjust_up(int child)
		{
			Compare com;
			int parent = (child - 1) / 2;
			while (child > 0 && com(_con[parent], _con[child]))
			{
				std::swap(_con[child], _con[parent]);
				child = parent;
				parent = (child - 1) / 2;
			}
		}

		void adjust_down(int parent)
		{
			Compare com;
			size_t child = parent * 2 + 1;
			while (child < _con.size())
			{
				if (child + 1 < _con.size() && com(_con[child], _con[child + 1]))
					++child;
				if (com(_con[parent], _con[child]))
				{
					std::swap(_con[child], _con[parent]);
					parent = child;
					child = parent * 2 + 1;
				}
				else
					break;
			}
		}

	private:
		Container _con;
	};
}
